Leveraging on-Site EVs for Enhanced Stationary Battery Utilization and Reliability in Base Stations

High-reliability telecom base stations (BSs) are a key enabler of sustainable 6G networks, yet guaranteeing resilience to power grid outages often forces their stationary battery energy storage systems (BESSs) to operate conservatively, leading to underutilization during normal operation. This paper presents a novel framework that integrates electric vehicles (EVs) parked at BS sites as a dynamic energy reserve, improving BS resilience during power grid outages while simultaneously reducing operating costs under normal conditions. By leveraging EV availability, the stationary BESS can safely operate at deeper depths of discharge (DOD) without compromising backup reliability, enabling energy arbitrage when the grid is available. The proposed methodology incorporates detailed models of battery aging, stochastic power grid outages, probabilistic EV availability, and the associated EV reserve compensation costs. Comparative case studies show that EV involvement reduces unmet energy demand during outages by 74% and more than triples the served traffic, while lowering total operating costs by 6.7% during normal operation. These results demonstrate that EV-assisted BESS management effectively decouples resilience requirements from economic operations, thereby strengthening the robustness and cost efficiency of next-generation telecommunications infrastructure.